U.S. patent application number 13/581507 was filed with the patent office on 2012-12-20 for array antenna apparatus.
This patent application is currently assigned to Mitsubishi Electric Corporation. Invention is credited to Tomohiro Akiyama, Ryoji Hayashi, Morishige Hieda, Yoshihito Hirano, Akira Inoue, Hiroyuki Joba, Kazutomi Mori, Kiyohide Sakai, Mitsuhiro Shimozawa, Kenichi Tajima, Yoshinori Takahashi.
Application Number | 20120319746 13/581507 |
Document ID | / |
Family ID | 44542053 |
Filed Date | 2012-12-20 |
United States Patent
Application |
20120319746 |
Kind Code |
A1 |
Hayashi; Ryoji ; et
al. |
December 20, 2012 |
ARRAY ANTENNA APPARATUS
Abstract
An array antenna apparatus in which an SN ratio is improved.
Antenna elements having transmission modules, respectively, are
arranged in plurality, wherein the plurality of transmission
modules respectively have transmission signal generators that each
output a transmission intermediate frequency signal, local
oscillation signal generators that each output a local oscillation
signal, and transmission mixers that each mix the transmission
intermediate frequency signal and the local oscillation signal with
each other, thereby to carry out frequency conversion to a
transmission high frequency signal. A reference signal source
inputs a reference signal to the transmission signal generators and
the local oscillation signal generators. The transmission
intermediate frequency signal and the local oscillation signal are
synchronized with each other by the reference signal.
Inventors: |
Hayashi; Ryoji; (Tokyo,
JP) ; Hirano; Yoshihito; (Tokyo, JP) ; Sakai;
Kiyohide; (Tokyo, JP) ; Shimozawa; Mitsuhiro;
(Tokyo, JP) ; Inoue; Akira; (Tokyo, JP) ;
Hieda; Morishige; (Tokyo, JP) ; Joba; Hiroyuki;
(Tokyo, JP) ; Tajima; Kenichi; (Tokyo, JP)
; Takahashi; Yoshinori; (Tokyo, JP) ; Mori;
Kazutomi; (Tokyo, JP) ; Akiyama; Tomohiro;
(Tokyo, JP) |
Assignee: |
Mitsubishi Electric
Corporation
Chiyoda-ku, Tokyo
JP
|
Family ID: |
44542053 |
Appl. No.: |
13/581507 |
Filed: |
February 22, 2011 |
PCT Filed: |
February 22, 2011 |
PCT NO: |
PCT/JP2011/053811 |
371 Date: |
August 28, 2012 |
Current U.S.
Class: |
327/141 |
Current CPC
Class: |
H01Q 21/0025 20130101;
H01Q 3/42 20130101; H04B 17/0085 20130101; H01Q 3/30 20130101 |
Class at
Publication: |
327/141 |
International
Class: |
H03L 7/00 20060101
H03L007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 4, 2010 |
JP |
2010-047945 |
Claims
1-9. (canceled)
10. An array antenna apparatus comprising: a plurality of antenna
elements having transmission modules, respectively; wherein each of
said plurality of transmission modules includes: a transmission
signal generator that outputs a transmission intermediate frequency
signal; a local oscillation signal generator that outputs a local
oscillation signal; and a transmission mixer that mixes said
transmission intermediate frequency signal and said local
oscillation signal with each other thereby to carry out frequency
conversion to a transmission high frequency signal; wherein a
reference signal source is provided which inputs a reference signal
to said transmission signal generators and said local oscillation
signal generators; and said transmission intermediate frequency
signal and said local oscillation signal are synchronized with each
other by said reference signal.
11. The array antenna apparatus as set forth in claim 10, wherein:
a phase control part is provided which outputs phase control
signals to said transmission signal generators, respectively; and
the phases of said transmission intermediate frequency signals are
controlled by the phase control signals, respectively.
12. The array antenna apparatus as set forth in claim 10, wherein:
a phase control part is provided which outputs phase control
signals to said local oscillation signal generators, respectively;
and the phases of said local oscillation signals are controlled by
the phase control signals, respectively.
13. The array antenna apparatus as set forth in claim 10, wherein:
a timing control part is provided which outputs timing control
signals to said transmission signal generators, respectively; and
the signal generation timings of said transmission intermediate
frequency signals are controlled by said timing control signals,
respectively.
14. An array antenna apparatus comprising: a plurality of antenna
elements having transmission and reception modules, respectively;
wherein each of said plurality of transmission and reception
modules includes: a transmission signal generator that outputs a
transmission intermediate frequency signal; a local oscillation
signal generator that outputs a local oscillation signal; a
transmission mixer that mixes said transmission intermediate
frequency signal and said local oscillation signal with each other
thereby to carry out frequency conversion to a transmission high
frequency signal; and a reception mixer that mixes said local
oscillation signal and a reception high frequency signal with each
other, thereby to carry out frequency conversion to a reception
intermediate frequency signal; wherein a reference signal source is
provided which inputs a reference signal to said transmission
signal generators and said local oscillation signal generators; a
signal synthesizer is provided which synthesizes said plurality of
reception intermediate frequency signals outputted from the
individual reception mixers in said plurality of transmission and
reception modules, respectively; and wherein said transmission
intermediate frequency signal and said local oscillation signal are
synchronized with each other by said reference signal.
15. The array antenna apparatus as set forth in claim 14, wherein:
a phase control part is provided which outputs phase control
signals to said transmission signal generators, respectively; and
the phases of said transmission intermediate frequency signals are
controlled by the phase control signals, respectively.
16. The array antenna apparatus as set forth in claim 14, wherein:
a phase control part is provided which outputs phase control
signals to said local oscillation signal generators, respectively;
and the phases of said local oscillation signals are controlled by
the phase control signals, respectively.
17. The array antenna apparatus as set forth in claim 14, wherein:
a timing control part is provided which outputs timing control
signals to said transmission signal generators, respectively; and
the signal generation timings of said transmission intermediate
frequency signals are controlled by said timing control signals,
respectively.
18. An array antenna apparatus comprising: a plurality of antenna
elements having transmission and reception modules, respectively;
wherein each of said plurality of transmission and reception
modules includes: a transmission signal generator that outputs a
transmission intermediate frequency signal; a local oscillation
signal generator that outputs a local oscillation signal; a
transmission mixer that mixes said transmission intermediate
frequency signal and said local oscillation signal with each other
thereby to carry out frequency conversion to a transmission high
frequency signal; a reception local oscillation signal generator
that outputs a reception local oscillation signal; and a reception
mixer that mixes said reception local oscillation signal and a
reception high frequency signal with each other, thereby to carry
out frequency conversion to a reception intermediate frequency
signal or a reception base band signal; wherein a reference signal
source is provided which inputs a reference signal to said
transmission signal generators, said local oscillation signal
generators and said reception local oscillation signal generators;
a signal synthesizer is provided which synthesizes said plurality
of reception intermediate frequency signals or reception base band
signals outputted from the individual reception mixers in said
plurality of transmission and reception modules, respectively; and
wherein said transmission intermediate frequency signal, said local
oscillation signal and said reception local oscillation signal are
synchronized with one another by said reference signal.
19. The array antenna apparatus as set forth in claim 18, wherein:
a phase control part is provided which outputs phase control
signals to said transmission signal generators, respectively; and
the phases of said transmission intermediate frequency signals are
controlled by the phase control signals, respectively.
20. The array antenna apparatus as set forth in claim 18, wherein:
a phase control part is provided which outputs phase control
signals to said local oscillation signal generators, respectively;
and the phases of said local oscillation signals are controlled by
the phase control signals, respectively.
21. The array antenna apparatus as set forth in claim 18, wherein:
a timing control part is provided which outputs timing control
signals to said transmission signal generators, respectively; and
the signal generation timings of said transmission intermediate
frequency signals are controlled by said timing control signals,
respectively.
22. The array antenna apparatus as set forth in claim 18. wherein:
a phase control part is provided which outputs phase control
signals to said local oscillation signal generators and said
reception local oscillation signal generators, respectively; and
the phases of said local oscillation signals and the reception
local oscillation signals are controlled by said phase control
signals, respectively.
Description
TECHNICAL FIELD
[0001] The present invention relates to an array antenna apparatus
which is constructed by arranging a plurality of antenna
systems.
BACKGROUND ART
[0002] In the past, there have been proposed a variety of kinds of
constructions in array antennas apparatuses (for example, refer to
a first patent document and a first nonpatent document).
[0003] A conventional array antenna apparatus as shown in the first
patent document is provided with a plurality of antenna elements, a
plurality of transmission and reception modules that are connected
to the individual antenna elements, respectively, and a
distributing and synthesizing device that distributes transmission
intermediate frequency signals to the plurality of transmission and
reception modules (or synthesizes reception intermediate frequency
signals from the plurality of transmission and reception
modules).
[0004] In addition, each transmission and reception module is
provided with a first duplexer that sends a transmission high
frequency signal to each antenna element (or receives a reception
high frequency signal from the antenna element), a transmission
amplifier that amplifies the transmission high frequency signal and
sends it to the duplexer, a reception amplifier that amplifies a
reception high frequency signal from the duplexer, a second
duplexer that sends the transmission high frequency signal to the
transmission amplifier (or receives the reception high frequency
signal from the reception amplifier), a mixer that is combined with
the second duplexer and produces the transmission high frequency
signal from a local oscillation signal and an intermediate
frequency signal from the outside (or produces a reception
intermediate frequency signal from the local oscillation signal and
the reception high frequency signal), and a local oscillation
signal generator.
[0005] In the above-mentioned construction of the first patent
document, a clock signal and a trigger signal are inputted to the
local oscillation signal generator from the outside, so that the
synchronization of local oscillation signals generated by the
individual transmission and reception modules is taken therein.
[0006] In this manner, transmission loss at the time of
distributing and combining or synthesizing signals or supplying
electric power to the modules is suppressed by using intermediate
frequency signals instead of high frequency signals as the
transmission and reception signals which are inputted to or
outputted from the transmission and reception modules of the array
antenna apparatus.
[0007] On the other hand, in the case of another conventional array
antenna apparatus as shown in the first nonpatent document, in a
transmission array, antenna elements are grouped into a plurality
of groups, each of which comprises a plurality of antenna elements
arranged in proximity with one another, and the antenna elements of
each group are connected to one another through a signal
distributor which is composed of a plurality of transmission signal
generators and a cross point switch.
[0008] In the above-mentioned construction in the first patent
document, it is constructed such that the transmission high
frequency signals generated by the transmission signal generators
are distributed to supply electric power to the antenna elements of
arbitrary groups, wherein by dividing an aperture plane of a
transmission array antenna, the thus divided parts thereof are
assigned to a plurality of communications, electronic warfare
systems, radars, etc., respectively, so that they can be used at
the same time.
PRIOR ART REFERENCES
Patent Documents
[0009] [First Patent Document] Japanese patent application
laid-open No. H11-266112
Nonpatent Documents
[0010] [First Nonpatent Document] "The Advanced Multifunction RF
Concept", G. C. Tavik, et al., IEEE Transactions on Microwave
Theory and Techniques, Vol.53, No.3, March 2005
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0011] Among the conventional array antenna apparatuses, the
apparatus described in the first patent document has had the
following problem. That is, the same transmission intermediate
frequency signal has been distributed to transmission and reception
modules of a plurality of antenna elements, so it is impossible to
perform aperture division in which different transmission signals
are transmitted to the individual antenna elements thus grouped,
respectively, so that one and the same array antenna apparatus can
be used as a plurality of communication systems, electronic warfare
systems, radars, and so on at the same time.
[0012] In addition, in the apparatus described in the
above-mentioned first nonpatent document, there has been a problem
that the transmission signals generated by the transmission signal
generators are high frequency signals, and hence, transmission loss
is large due to the distribution of the transmission high frequency
signals to the antenna elements.
[0013] The present invention has been made in order to solve the
problems as referred to above, and has for its object to obtain an
array antenna apparatus in which an SN ratio is improved.
Means for Solving the Problems
[0014] An array antenna apparatus according to the present
invention is constructed such that a plurality of antenna elements
having transmission modules, respectively, are arranged, and each
of the plurality of transmission modules includes a transmission
signal generator that outputs a transmission intermediate frequency
signal, a local oscillation signal generator that outputs a local
oscillation signal, and a transmission mixer that mixes the
transmission intermediate frequency signal and the local
oscillation signal with each other thereby to carry out frequency
conversion to a transmission high frequency signal, wherein a
reference signal source is provided which inputs a reference signal
to the transmission signal generator and the local oscillation
signal generator, and the transmission intermediate frequency
signal and the local oscillation signal are synchronized with each
other by the reference signal.
Effect of the Invention
[0015] According to the present invention, by combining the
transmission high frequency signals generated from a plurality of
(n) local oscillation signals with one another, it is possible to
improve an SN ratio by n times in comparison with the case where a
transmission high frequency signal generated from a single local
oscillation signal is amplified by n times.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a block diagram showing a first construction
example of an array antenna apparatus according to a first
embodiment of the present invention. (First Embodiment)
[0017] FIG. 2 is a block diagram showing a second construction
example of an array antenna apparatus according to the first
embodiment of the present invention. (First Embodiment)
[0018] FIG. 3 is a block diagram showing a first construction
example of an array antenna apparatus according to a second
embodiment of the present invention. (Second Embodiment)
[0019] FIG. 4 is a block diagram showing a second construction
example of an array antenna apparatus according to the second
embodiment of the present invention. (Second Embodiment)
[0020] FIG. 5 is a block diagram showing a first construction
example of an array antenna apparatus according to a third
embodiment of the present invention. (Third Embodiment)
[0021] FIG. 6 is a block diagram showing a second construction
example of an array antenna apparatus according to a third
embodiment of the present invention. (Third Embodiment)
[0022] FIG. 7 is a block diagram showing a construction example of
an array antenna apparatus according to a fourth embodiment of the
present invention. (Fourth Embodiment)
MODES FOR CARRYING OUT THE INVENTION
First Embodiment
[0023] FIG. 1 and FIG. 2 are block diagrams showing an array
antenna apparatus according to a first embodiment of the present
invention, and these figures show different construction examples,
respectively.
[0024] Here, only transmission modules 20a-20n of a plurality of
(n) antenna elements 10a-10n are shown, but it is assumed that each
of the antenna elements 10a-10n is also provided with a reception
module (to be described later together with FIG. 5 and FIG. 6), and
that each of the antenna elements 10a-10n is composed of a
transmission and reception antenna.
[0025] In FIG. 1 and FIG. 2, the array antenna apparatus is
constructed such that n (n being an arbitrary natural number more
than "1") antenna elements 10a-10n having individual transmission
modules 20a-20n, respectively, are arranged in plurality.
[0026] Because the transmission modules 20a-20n are each
constructed by the same circuit arrangement, the individual circuit
elements within the transmission modules 20a-20n are denoted by the
same symbols with "a, b, . . . , n" being affixed thereafter,
respectively.
[0027] Typically, focusing on the antenna element 10a at the
left-hand end in FIG. 1, the transmission module 20a is provided
with a transmission signal generator 11a that outputs a
transmission intermediate frequency signal S1, a local oscillation
signal generator 21a that outputs a local oscillation signal S2, a
transmission mixer 12a that mixes the transmission intermediate
frequency signal S1 and the local oscillation signal S2 with each
other thereby to carry out frequency conversion to a transmission
high frequency signal S3, and a transmission power amplifier 13a
that amplifies the transmission high frequency signal S3.
[0028] A reference signal source 1 is connected to the individual
transmission modules 20a-20n, respectively, through a signal
distributor 2, wherein the reference signal source 1 generates a
reference signal Sr, and inputs the reference signal Sr to the
transmission signal generators 11a-11n and the local oscillation
signal generators 21a-21n within the individual transmission
modules 20a-20n through the signal distributor 2.
[0029] As a result of this, the transmission intermediate frequency
signal S1 outputted from each of the transmission signal generators
11a-11n and the local oscillation signal S2 outputted from each of
the local oscillation signal generators 21a-21n are made to
synchronize by means of the reference signal Sr.
[0030] The individual antenna elements 10a-10n transmit the
transmission high frequency signals S3 amplified by the
transmission power amplifiers 13a-13n as electric waves,
respectively.
[0031] Here, note that an arbitrary element can be applied to the
local oscillation signal generator 21a as long as it generates a
local oscillation signal S2 in synchronization with a reference
signal Sr, and it may be composed of an injection locked
oscillator, or may be composed of a phase locked loop (PLL).
[0032] In addition, in FIG. 1, a phase control part 3A is connected
to the individual transmission signal generators 11a-11n within the
transmission modules 20a-20n, respectively, wherein the phase
control part 3A inputs phase control signals P1 to the transmission
signal generators 11a-11n, respectively, so that it controls the
phases of the transmission intermediate frequency signals S1 from
the transmission signal generators 11a-11n, respectively.
[0033] On the other hand, in FIG. 2, a phase control part 3B is
connected to the individual local oscillation signal generators
21a-21n within the transmission modules 20a-20n, respectively,
wherein the phase control part 3B inputs phase control signals P2
to the local oscillation signal generators 21a-21n, so that it
controls the phases of the local oscillation signals S2 from the
local oscillation signal generators 21a-21n, respectively.
[0034] In any of the cases of FIG. 1 and FIG. 2, too, the phases of
the transmission high frequency signals S3 outputted from the
transmission power amplifiers 13a-13n are controlled under the
control of the phase control parts 3A, 3B, and hence, it becomes
possible to control the shapes and directions of the transmission
beams from the antenna elements 10a-10n.
[0035] In FIG. 1, in order to control the phases of the
transmission intermediate frequency signals S1 from the
transmission signal generators 11a-11n by means of the phase
control signals P1, respectively, for example, the transmission
signal generators 11a-11n may be composed of direct digital
synthesizers, respectively, wherein the phases of the output
signals of the direct digital synthesizers are controlled.
[0036] Alternatively, phase shifters (not shown) may be arranged at
output parts of the transmission signal generators 11a-11n,
respectively, so that the phase shifters are controlled.
[0037] In addition, in FIG. 2, in order to control the phases of
the local oscillation signals S2 from the local oscillation signal
generators 21a-21n by means of the phase control signals P2,
respectively, for example, phase shifters (not shown) may be
arranged at output parts of the local oscillation signal generators
21a-21n, respectively, so that the phase shifters are controlled to
directly control the local oscillation signals S2,
respectively.
[0038] Alternatively, phase shifters (not shown) may be arranged at
input parts of the local oscillation signal generators 21a-21n,
respectively, to which the reference signals Sr are inputted, so
that the phase shifters are controlled to control the reference
signals Sr, respectively.
[0039] Next, reference will be made to an operation of the array
antenna apparatus according to the first embodiment of the present
invention, while referring to FIG. 1 and FIG. 2.
[0040] In the transmission modules 20a-20n, the transmission mixers
12a-12n respectively mix the transmission intermediate frequency
signals S1 outputted from the transmission signal generators
11a-11n, respectively, and the local oscillation signals S2
outputted from the local oscillation signal generators 21a-21n,
respectively, so that they generate the transmission high frequency
signals S3, respectively, by means of frequency conversion.
[0041] The transmission high frequency signals S3 are amplified by
the transmission power amplifiers 13a-13n, respectively, and
thereafter are transmitted from the antenna elements 10a-10n,
respectively.
[0042] At this time, the transmission intermediate frequency
signals S1 and the local oscillation signals S2 are synchronized
with the reference signal Sr which is distributed and inputted
through the signal distributor 2, as mentioned above, so that the
transmission high frequency signals S3 are also synchronized with
the reference signal Sr.
[0043] Accordingly, by controlling the phases of the transmission
high frequency signals S3 by means of the phase control signals P1
of the phase control part 3A or the phase control signals P2 of the
phase control part 3B, it becomes possible to control the shapes
and directions of transmission beams to be transmitted from the
individual antenna elements 10a-10n, respectively.
[0044] In addition, the local oscillation signal generators 21a-21n
are independently arranged for the antenna elements 10a-10n,
respectively, and hence, the fluctuations (phase noise) in the
frequencies of the local oscillation signals S2 are also
independent from one another.
[0045] Accordingly, when the phases of the transmission high
frequency signals S3 are controlled to form the transmission beams
through vector synthesis of the signals, respectively, the signals
are subjected to amplitude synthesis or combination, but on the
other hand, the phase noises contained in the transmission high
frequency signals S3 are subjected to electric power synthesis or
combination.
[0046] In other words, by combining or synthesizing the
transmission high frequency signals S3 generated from the n local
oscillation signals S2 with one another, it is possible to improve
an SN ratio by n times in comparison with the case where a
transmission high frequency signal generated from a single local
oscillation signal is amplified by n times.
[0047] As described above, the array antenna apparatus according to
the first embodiment (FIG. 1 and FIG. 2) of the present invention
is constructed such that the plurality of (n) antenna elements 10a
-10n having the transmission modules 20a-20n, respectively, are
arranged.
[0048] The plurality of transmission modules 20a-20n respectively
have, as individual elements, the transmission signal generators
11a-11n that each output a transmission intermediate frequency
signal S1, the local oscillation signal generators 21a-21n that
each output a local oscillation signal S2, and the transmission
mixers 12a-12n that each mix the transmission intermediate
frequency signal S1 and the local oscillation signal S2 with each
other, thereby to carry out frequency conversion to a transmission
high frequency signal S3.
[0049] In addition, the array antenna apparatus according to the
first embodiment of the present invention is provided with the
reference signal source 1 that inputs a reference signal Sr to the
transmission signal generators 11a-11n and the local oscillation
signal generators 21a-21n, respectively, wherein the transmission
intermediate frequency signals S1 and the local oscillation signals
S2 are synchronized with each other by the reference signal Sr.
[0050] Moreover, in the construction example in FIG. 1, the phase
control part 3A is provided which outputs phase control signals P1
to the transmission signal generators 11a-11n, respectively,
wherein the phases of the transmission intermediate frequency
signals S1 are controlled by the phase control signals P1,
respectively.
[0051] On the other hand, in the construction example in FIG. 2,
the phase control part 3B is provided which outputs phase control
signals P2 to the local oscillation signal generators 21a-21n,
respectively, wherein the phases of the local oscillation signals
S2 are controlled by the phase control signals P1,
respectively.
[0052] In any of the construction examples in FIG. 1 and FIG. 2,
too, by combining the transmission high frequency signals S3
generated based on the plurality of (n) local oscillation signal
generators 21a-21n with one another, it is possible to improve the
SN ratio by n times in comparison with the case where a
transmission high frequency signal generated from a single local
oscillation signal is amplified by n times.
Second Embodiment
[0053] Here, note that in the above-mentioned first embodiment
(FIG. 1 and FIG. 2), only the phases of the transmission signal
generators 11a-11n or the phases of the local oscillation signal
generators 21a-21n have been controlled, but the timings of the
transmission signal generators 11a-11n may be controlled, as shown
in FIG. 3 or FIG. 4.
[0054] FIG. 3 and FIG. 4 are block diagrams showing construction
examples of an array antenna apparatus according to a second
embodiment of the present invention, wherein similarly as stated
above, these figures show only transmission modules 20a-20n, but
the different construction examples, respectively.
[0055] In FIG. 3 and FIG. 4, those which are similar to the
aforementioned ones (see FIG. 1 and FIG. 2) are denoted by the same
reference numerals and characters as those in the aforementioned
ones, while omitting a detailed explanation thereof.
[0056] In FIG. 3, it is different from FIG. 1 only in that a phase
and timing control part 4 is provided in place of the phase control
part 3A in FIG. 1.
[0057] In FIG. 3, the phase and timing control part 4 inputs not
only phase control signals P1 but also timing control signals T to
the transmission signal generators 11a-11n, so that it controls the
phases and signal generation timings of transmission intermediate
frequency signals S1 outputted by the transmission signal
generators 11a-11n, respectively.
[0058] On the other hand, in FIG. 4, it is different from FIG. 2
only in that a timing control part 5 is provided, in addition to
the construction in FIG. 2.
[0059] In FIG. 4, the timing control part 5 inputs timing control
signals T to the transmission signal generators 11a-11n,
respectively, so that it controls the signal generation timings of
transmission intermediate frequency signals S1 outputted from the
transmission signal generators 11a-11n, respectively. In addition,
similarly as stated above, the phase control part 3B inputs phase
control signals P2 to the local oscillation signal generators
21a-21n, respectively, so that it controls the phases of the local
oscillation signals S2 generated by the local oscillation signal
generators 21a-21n, respectively.
[0060] As described above, the array antenna apparatus according to
the second embodiment (FIG. 3 and FIG. 4) of the present invention
is provided, in the construction example of FIG. 3, with the phase
and timing control part 4 that outputs the phase control signals P1
and the timing control signals T to the transmission signal
generators 11a-11n, respectively, so that the phases of the
transmission intermediate frequency signals S1 are controlled, and
at the same time, the signal generation timings of the transmission
intermediate frequency signals S1 are controlled by the timing
control signals T, respectively.
[0061] In addition, in the construction example in FIG. 4, the
timing control part 5 is provided which outputs timing control
signals T to the transmission signal generators 11a-11n,
respectively, wherein the signal generation timings of the
transmission intermediate frequency signals S1 are controlled by
the timing control signals T, respectively.
[0062] As a result of this, in any of the cases of FIG. 3 and FIG.
4, too, the phases and signal generation timings of transmission
high frequency signals S3 outputted from the transmission mixers
12a-12n, respectively, are controlled, and hence, even if the
antenna elements 10a-10n are arranged in a discretely distributed
manner (i.e., in cases where the distances from the individual
antenna elements 10a-10n to a target are different from one
another), the timings of the transmission high frequency signals S3
outputted from the antenna elements 10a-10n, respectively, can be
controlled in such a manner that the timings of the electric waves
(the transmission high frequency signals S3) at which they arrives
at the target from the individual antenna elements 10a-10n are in
match or coincidence with one another.
[0063] Moreover, in FIG. 3, the phase control signals P1 and the
timing control signals T from the phase and timing control part 4
can be outputted in parallel form or in serial form.
[0064] For example, in cases where the phase control signals P1 and
the timing control signals T are outputted in serial form, it is
possible to reduce the number of wirings to be distributed to the
individual local oscillation signal generators 21a-21n (individual
transmission and reception modules).
Third Embodiment
[0065] Here, note that in the above-mentioned first and second
embodiments (FIG. 1 through FIG. 4), there has been shown the case
where the invention is applied only to the transmission modules
20a-20n, but it may also be applied to transmission and reception
modules 30a-30n (transmission modules and reception modules), as
shown in FIG. 5 or FIG. 6.
[0066] FIG. 5 and FIG. 6 are block diagrams showing an array
antenna apparatus according to a third embodiment of the present
invention, and these figures show different construction examples,
respectively.
[0067] In FIG. 5 and FIG. 6, those which are similar to the
aforementioned ones (see FIG. 1 through FIG. 4) are denoted by the
same reference numerals and characters as those in the
aforementioned ones, while omitting a detailed explanation
thereof.
[0068] In FIG. 5, the transmission and reception modules 30a-30n
are provided, as individual elements, with duplexers 22a-22n, high
frequency amplifiers 31a-31n, and reception mixers 32a-32n,
respectively, in addition to the components of the above-mentioned
transmission modules 20a-20n.
[0069] In addition, connected to the individual transmission and
reception modules 30a-30n, is a reception part 7 through a signal
synthesizer 6, in addition to the reference signal source 1, the
signal distributor 2, and the phase control part 3B, as referred to
above (FIG. 2).
[0070] The duplexers 22a-22n are inserted between the antenna
elements 10a-10n and the transmission power amplifiers 13a-13n,
respectively, and between the antenna elements 10a-10n and the high
frequency amplifiers 31a-31n, respectively, so that they switch or
select passing signals, respectively, in accordance with a
transmission mode and a reception mode.
[0071] That is, the duplexers 22a-22n are to share the same antenna
elements 10a-10n, respectively, in the transmission and reception
modes, and for example, circulators may be used for them,
respectively.
[0072] The high frequency amplifiers 31a-31n amplify the signals
received by the antenna elements 10a-10n, respectively.
[0073] The reception mixers 32a-32n respectively mix reception high
frequency signals S4 outputted from the high frequency amplifiers
31a-31n, respectively, and the local oscillation signals S2
outputted from the local oscillation signal generators 21a-21n,
respectively, so that they generate reception intermediate
frequency signals S5, respectively, by means of frequency
conversion, and input the reception intermediate frequency signals
S5 to the signal synthesizer 6.
[0074] In this case, the local oscillation signals S2 from the
local oscillation signal generators 21a-21n are inputted to both
the transmission mixers 12a-12n and the reception mixers 32a-32n,
respectively.
[0075] The signal synthesizer 6 synthesizes the reception
intermediate frequency signals S5 from the reception mixers
32a-32n, and inputs a synthesized signal thus obtained to the
reception part 7.
[0076] As described above, in the array antenna apparatus according
to the third embodiment (FIG. 5) of the present invention, the
antenna elements 10a-10n having the transmission and reception
modules 30a-30n, respectively, are arranged in plurality, wherein
the plurality of transmission and reception modules 30a-30n have,
as individual elements, the transmission signal generators 11a-11n
that each output a transmission intermediate frequency signal S1,
the local oscillation signal generators 21a-21n that each output a
local oscillation signal S2, the transmission mixers 12a-12n that
each mix the transmission intermediate frequency signal S1 and the
local oscillation signal S2 with each other, thereby to carry out
frequency conversion to a transmission high frequency signal S3,
and the reception mixers 32a-32n that each mix the local
oscillation signal S2 and the reception high frequency signal S4
with each other, thereby to carry out frequency conversion to the
reception intermediate frequency signal S5.
[0077] In addition, the array antenna apparatus according to the
third embodiment (FIG. 5) of the present invention is provided with
the reference signal source 1 that inputs a reference signal Sr to
the transmission signal generators 11a-11n and the local
oscillation signal generators 21a-21n, and the signal synthesizer 6
that synthesizes the plurality of reception intermediate frequency
signals S5 outputted from the individual reception mixers 32a-32n
in the plurality of transmission and reception modules 30a-30n,
respectively.
[0078] The transmission intermediate frequency signals S1 and the
local oscillation signals S2 are synchronized with each other by
the reference signal Sr.
[0079] In this manner, by making the local oscillation signals S2
used for the frequency conversion in the transmission mixers
12a-12n and the local oscillation signals S2 used for the frequency
conversion in the reception mixers 32a-32n identical with each
other, it is possible to cancel the influence of fluctuation in the
frequency of the local oscillation signals S2 (phase noise
contained in the local oscillation signals S2).
[0080] Moreover, similar to the case of the transmission signals,
it is constructed such that the signal synthesizer 6 is arranged at
the reception signal side, too, so as to synthesize the reception
intermediate frequency signals S5 generated from n local
oscillation signals S2. As a result, the SN ratio can be improved
by n times in comparison with the case where a reception
intermediate frequency signal generated from a single local
oscillation signal is amplified by n times.
[0081] Further, by the provision of the phase control part 3B
similar to the above-mentioned one (FIG. 2), the phases of the
transmission high frequency signals S3 outputted from the
transmission power amplifiers 13a-13n are controlled under the
control of the phase control part 3B, similarly as stated above, so
that it becomes possible to control the shapes and directions of
the transmission beams from the antenna elements 10a-10n.
[0082] In addition, in FIG. 5, the phase control part 3B is
provided for the local oscillation signal generators 21a-21n, but
similar to FIG. 1, a phase control part 3A may be provided for the
transmission signal generators 11a-11n, or similar to FIG. 3 (or
FIG. 4), a phase and timing control part 4 (or a timing control
part 5) may be provided for the transmission signal generators
11a-11n, and in any case, too, the same operational effects as
those mentioned above are achieved.
[0083] Here, note that in FIG. 5, the local oscillation signals S2
generated from the same local oscillation signal generators 21a-21n
are inputted to both the transmission mixers 12a-12n and the
reception mixers 32a-32n, respectively, but as shown in FIG. 6,
reception local transmission signal generators 23a-23n, which
output reception local oscillation signals S6 to the reception
mixers 32a-32n, respectively, may be provided, separately from the
local oscillation signal generators 21a-21n for the transmission
mixers 12a-12n.
[0084] That is, in FIG. 6, the transmission and reception modules
30a-30n of the array antenna apparatus according to the third
embodiment of the present invention have, as individual elements,
in addition to the transmission signal generators 11a-11n, the
local oscillation signal generators 21a-21n and the transmission
signal mixers 12a-12n, the local oscillation signal generators
21a-21n that each output a local oscillation signal S2, and the
reception mixers 32a that each mix the local oscillation signal S2
and the reception high frequency signal S4 with each other, thereby
to carry out frequency conversion to the reception intermediate
frequency signal S5.
[0085] Here, note that in the above description, the output signals
of the reception mixers 32a-32n are used as the reception
intermediate frequency signals S5, but in the third embodiment of
the present invention, the individual frequencies of the local
oscillation signals S2 and the reception local oscillation signals
S6 may not be the same with each other, and hence, the output
signals of the reception mixers 32a-32n can also be used as
reception base band signals, in place of the reception intermediate
frequency signals S5.
[0086] Moreover, the array antenna apparatus according to the third
embodiment (FIG. 6) of the present invention is provided with the
reference signal source 1 that inputs a reference signal Sr to the
transmission signal generators 11a-11n, the local oscillation
signal generators 21a-21n and the reception local oscillation
signal generators 23a-23n, and the signal synthesizer 6 that
synthesizes the reception intermediate frequency signals S5 (or
reception base band signals) outputted from the individual
reception mixers 32a-32n in the transmission and reception modules
30a-30n, respectively.
[0087] According to this, the transmission intermediate frequency
signals S1, the local oscillation signals S2 and the reception
local oscillation signals S6 are synchronized with one another by
the reference signal Sr.
[0088] In addition, the phase control signals P2 from the phase
control part 3B are inputted to the local oscillation signal
generators 21a-21n and the reception local oscillation signal
generators 23a-23n, respectively, whereby the phases of the local
oscillation signals S2 and the reception local oscillation signals
S6 are controlled by the phase control signals P1,
respectively.
Fourth Embodiment
[0089] Here, note that in the above-mentioned first and second
embodiments (FIG. 1 through FIG. 4), there has been shown the case
where the invention is applied only to the transmission modules
20a-20n, and in the above-mentioned third embodiment (FIG. 5 and
FIG. 6), there has been showed the case where the invention is
applied to the transmission and reception modules 30a-30n, but the
invention may be applied only to reception modules 40a-40n
(reception modules), as shown in FIG. 7.
[0090] FIG. 7 is a block diagram showing a construction example of
an array antenna apparatus according to a fourth embodiment of the
present invention, wherein those which are similar to the
aforementioned ones (see FIG. 1 through FIG. 6) are denoted by the
same reference numerals and characters as those in the
aforementioned ones, while omitting a detailed explanation
thereof.
[0091] In FIG. 7, the transmission and reception modules 40a-40n
are respectively provided, as individual elements, with reception
local oscillation signal generators 23a-23n, high frequency
amplifiers 31a-31n, and reception mixers 32a-32n.
[0092] In addition, connected to the individual transmission and
reception modules 40a-40n, is a reception part 7 through a signal
synthesizer 6, in addition to the reference signal source 1, the
signal distributor 2, and the phase control part 3B, as referred to
above (FIG. 2).
[0093] The high frequency amplifiers 31a-31n amplify the signals
received by the antenna elements 10a-10n, respectively.
[0094] The reception mixers 32a-32n respectively mix reception high
frequency signals S4 outputted from the high frequency amplifiers
31a-31n, respectively, and the reception local oscillation signals
S6 outputted from the reception local oscillation signal generators
23a-23n, respectively, so that they generate reception intermediate
frequency signals S5 (or reception base band signals),
respectively, by means of frequency conversion, and input the
reception intermediate frequency signals S5 (or the reception base
band signals) to the signal synthesizer 6.
[0095] The signal synthesizer 6 synthesizes the reception
intermediate frequency signals S5 (or the reception base band
signals) from the reception mixers 32a-32n, and inputs a
synthesized signal thus obtained to the reception part 7.
[0096] As described above, in the array antenna apparatus according
to the fourth embodiment (FIG. 7) of the present invention, the
antenna elements 10a-10n having the transmission and reception
modules 40a-40n, respectively, are arranged in plurality, wherein
the plurality of transmission and reception modules 40a-40n have,
as individual elements, the reception mixers 32a-32n that each mix
the reception local oscillation signal S6 and the reception high
frequency signal S4 with each other, thereby to carry out frequency
conversion to the reception intermediate frequency signal or the
reception base band signal S5.
[0097] Moreover, the array antenna apparatus according to the
fourth embodiment (FIG. 7) of the present invention is provided
with the reference signal source 1 that inputs a reference signal
Sr to the reception local oscillation signal generators 23a-23n,
and the signal synthesizer 6 that synthesizes the plurality of
reception intermediate frequency signals or reception baseband
signals S5 outputted from the individual reception mixers 32a-32n
in the plurality of transmission and reception modules 40a-40n,
respectively.
[0098] They are synchronized with the reception local oscillation
signals S6 by the reference signals Sr.
[0099] In this manner, similar to the case of the transmission
signals, it is constructed such that the signal synthesizer 6 is
arranged at the reception signal side, too, so as to synthesize the
reception intermediate frequency signals S5 generated from n local
oscillation signals S2. As a result, the SN ratio can be improved
by n times in comparison with the case where a reception
intermediate frequency signal generated from a single local
oscillation signal is amplified by n times.
[0100] Further, by the provision of the phase control part 3B
similar to the above-mentioned one (FIG. 2), the phases of the
reception intermediate frequency signals or the reception base band
signal S5 outputted from the reception mixers 32a-32n are
controlled under the control of the phase control part 3B,
similarly as stated above, so that it becomes possible to control
the shapes and directions of the reception beams from the antenna
elements 10a-10n.
EXPLANATION OF REFERENCE NUMERALS AND CHARACTERS
[0101] 1 reference signal source, 2 signal distributor, 3A, 3B
phase control parts, 4 phase and timing control part, 5 timing
control part, 6 signal synthesizer, 7 reception part, 10a-10n
antenna elements, 11a-11n transmission signal generators, 12a-12n
transmission mixers, 20a-20n transmission modules, 21a-21n local
oscillation signal generators, 22a-22n duplexers, 23a-23n reception
local oscillation signal generators, 30a-30n transmission and
reception modules, 32a-32n reception mixers, 40a-40n reception
modules, P1, P2 phase control signals, S1 transmission intermediate
frequency signal, S2 local oscillation signal, S3 transmission high
frequency signal, S4 reception high frequency signal, S5 reception
intermediate frequency signal, S6 reception local oscillation
signal, Sr reference signal, T timing control signal.
* * * * *